1st ray

1
1st Ray Elevatus
• The first ray (first metatarsal and medial cuneiform, above) is arguably the most
dominant mechanical structure of the forefoot. As a result, its proper function is
critical.1
• The naviculocuneiform joint contributes the most motion to the first ray, about 50%
in normal feet. The first metatarsocuneiform also contributes significantly with
41%.2
• Duchenne recognized in 1867 that the functional position of the first ray is
dependent on agonist-antagonist balance of the three extrinsic muscles which find
attachment on the first ray and navicular; peroneus longus, tibialis anterior, and
tibialis posterior.1
• Yet it wasn’t until 1938 that Lambrinudi reported on dorsal elevation of the first
metatarsal head as being an anatomical dysfunction.3
• Roukis et al. performed a study in 1996 which evaluated first ray dorsiflexion and its
effects on overall first ray mobility. Their results indicated a trend toward decreased
hallux dorsiflexion with subsequent elevation of the first ray.2
• A delicate balance of ligamentous and muscle support is required to maintain
functional segmental alignment of the first ray. The key contributors are outlined
below:1
Static stability (ligaments)
Intermetatarsal
Plantar metatarsocuneiform
Interosseous
Medial fibers of the central band of the plantar fascia
Dynamic stability (Muscle
support)
peroneus longus
tibialis anterior
tibialis posterior
extensor hallucis longus
• With metatarsus primus elevatus identified as a possible cause of hallux rigidus,
many authors suggested surgical alterations of this supposed pathology as a
treatment for the condition.3
• Modified versions of the Wilson, the Watermann and Reverdin-Green osteotomy as
well as the Austin bunionectomy were proposed to allow for correction of
metatarsus primus elevatus.2
• Elevation of the first ray was recognised as present in two thirds of patients with
hallux rigidus in a study by Bonney and Macnab in the 1950’s, but the study left the
question of whether the elevatus was the cause or simply a result of the hallux
rigidus.3
• In a study on the role of Metatarsus Primus Elevatus in the pathogenesis of Hallux
Rigidus, 264 lateral weightbearing radiographs were reviewed from 81 patients with
hallux rigidus, 64 patients diagnosed with isolated Morton's neuroma and 50
asymptomatic volunteers.3
• The table below compares the measurements of all three groups.

Comparison of Radiographic Parameters of the First Ray
Group Number of feet Metatarsus Primus
Elevatus
(mm ± SD)
1 st metatarsal
declination
(mm ± SD)
Difference, 1 st and 2 nd
metatarsal declination
(mm ± SD)
Hallux 100 7.8 ± 0.3 20.6 ± 0.3 3.7 ± 0.3
Rigidus
Neuroma 64 7.8 ± 0.3 20.9 ± 0.4 3.2 ± 0.3
Control 100 7.9 ± 0.2 20.2 ± 0.3 3.4 ± 0.2
• Analysis revealed no significant differences between groups for any of the
measurements examined (Table 1).3
• These results confirm that during mid-stance, elevation of the first ray seems to be a
normal radiographic finding.3
• Associations between metatarsus elevatus and hallux limitus have been previously
described in the literature, however it seems it is just as often refuted by others.2
• Coughlin and Shurnas examined the presence of first ray elevation in patients with
various grades of hallux rigidus after being treated with Cheilectomy or Arthrodesis.4
• Preoperatively, 120 (94%) of the 127 feet had <8 mm of elevation, which had been
determined as being the normal range.4
• This alone supports the argument that first ray elevation of up to the normal
expected amount does not strongly indicate a link to Hallux rigidus.4
• However there was a correlation between the postoperative grade of Hallux rigidus
and the amount of elevatus. The mean preoperative and postoperative
measurements of elevatus were 5.3 mm and 6.1 mm in the cheilectomy group. And
both before and following cheilectomy, an increased value for elevatus was
associated with a higher grade of hallux rigidus.4
• In summary, elevatus decreased postoperatively in patients with Grade-1 or 2 hallux
rigidus but it increased in those with Grade-3 or 4.4
• In contrast, the mean preoperative elevatus in the arthrodesis group was 5.6 mm,
and this was significantly reduced in those with Grade-3 or 4 hallux rigidus
postoperatively to 1.7 mm (difference in the means = 3.9 mm).4

• The researchers believe that when the joint has deteriorated clinically to the point
where elevation of the first ray is pronounced, metatarsophalangeal arthrodesis
should be the preferred treatment because first-ray elevation significantly
diminished after arthrodesis.4
• Given the discord of opinion regarding the causal relationship of metatarsus primus
elevatus and hallux deformities such as rigidus and limitus, the observation should
only be one facet of a comprehensive analysis of indications for surgeries such as
tarsometatarsal fusions.
• Proximally, tarsometatarsal fusions of the first ray (seen below) are also indicated to
treat patients with hypermobility of the first ray, failed primary hallux valgus surgery,
generalized ligamentous laxity, and arthritic changes of the first TMT joint.5
References
1. Christensen JC, Jennings MM. Normal and Abnormal Function of the First Ray. Clin
Podiatr Med Surg 2009; 26: 355–371. Elsevier (accessed 18 May 2012).
2. Hild GA, McKee PJ. Evaluation and Biomechanics of the First Ray in the Patient with
Limited Motion. Clin Podiatr Med Surg 2011; 28: 245-267. Elsevier (accessed 18 May
2012).
3. Horton GA, Park YW and Myerson MS. Role of Metatarsus Primus Elevatus in the
Pathogenesis of Hallux Rigidus. Foot & Ankle International 1999; 20(12): 777-780.
http://fai.sagepub.com/content/20/12/777 (accessed 20 May 2012).
4. Coughlin MJ, Shurnas PS. Hallux rigidus: Grading and long-term results of operative
treatment. Journal of Bone and Joint Surgery, American volume 2003; 85(11): 2072-
2088. ProQuest (accessed 18 May 2012).
5. Espinosa N, Wirth SH. Tarsometatarsal Arthrodesis for Management of Unstable First
Ray and Failed Bunion Surgery. Foot Ankle Clin N Am 2011; 16: 21-34. Elsevier
(accessed 20 May 2012).

1
Normal and Abnormal
Function of the
First Ray
3
Role of Metatarsus Primus Elevatus in the Pathogenesis of Hallux Rigidus
2
Evaluation and
Biomechanics of the
First Ray in the Patient
with Limited Motion
4
Coughlin, MJ & Shurnas, PS 2003, ‘Hallux rigidus: Grading and long-term results of operative
treatment’, Journal of Bone and Joint Surgery, American volume, vol. 85 no. 11 pp. 2072-
2088.
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Tarsometatarsal Arthrodesis for Management of Unstable First Ray and Failed Bunion
Surgery